Demographic Analysis of Spanish Population Pyramids and Urban Distribution
Analysis of Population Pyramids
A. Structural Review
Sex Ratio: Men are more numerous at birth, but higher male mortality rates lead to a larger elderly female population.
B. Age Structure Commentary
- Triangular or Parasol Shape (e.g., Spain in 1900): Characterized by a wide base due to high birth rates and a rapid decrease toward the top, reflecting high mortality rates and low life expectancy.
- Bell or Warhead Shape (Stationary): Indicates a stable adult population. The base is narrower as birth rates decline, allowing for generational replacement. The population decreases slowly toward the top due to lower mortality. Typically, 25% are young adults and 5-12% are elderly.
- Urn Shape (Aging Population): The base narrows due to low birth rates. The percentage of elderly individuals is high (+12%) due to increased life expectancy, which creates challenges for health and social welfare systems.
C. Significant Demographic Events
Indentations in the pyramid indicate population loss caused by sub-natality, mortality, wars, famines, epidemics, or emigration. Conversely, projections often show population increases due to economic development, post-war baby booms, or immigration.
Map of the Urban Axis
The largest population centers in Spain are the seven major cities: Bilbao, Seville, Madrid, Barcelona, Malaga, Valencia, and Zaragoza. Large cities often feature a semi-ring in the periphery, and their growth helps establish territorial lines.
Key Urban Axes
- Septentrional Axis: Discontinuous and presents articulation difficulties due to the absence of major metropolitan areas.
- Atlantic and Cantabrian Axes: Includes Ourense, Lugo, and Galicia, branching into the interior.
- Mediterranean Axis: Extends from Girona to Cartagena and is the most dynamic region.
- Andalusian Urban Network: Distributed along the Guadalquivir valley and the coastal axis.
- Ebro Valley Axis: Acts as a communication corridor between the Cantabrian and Mediterranean regions, centered on Zaragoza.
Large cities are concentrated in the northeast, with five major agglomerations exceeding half a million inhabitants: Madrid, Bilbao, Barcelona, Valencia, and Zaragoza.